The present invention relates to the determination of the moisture content of wood and, more particularly, to such determination by measuring electrical resistance through the wood.
During lumber processing operations, it is often necessary to determine the moisture content of the wood undergoing processing. To accomplish this function meter-type devices have been developed which determine the moisture content of wood based on the principle that the electrical resistance of wood varies with the moisture content. In these conventional devices, a DC voltage source is provided which develops a voltage potential across a pair of electrodes which are contacted with the wood at an appropriate distance from one another. The electrical properties exhibited by the circuit are dependent on the resistance of the wood. Measurements of one or more of the electrical properties of the circuit are used to determine the resistance of the wood, and this resistance is then correlated with a wood moisture content. These devices provide a rapid and convenient method of ascertaining wood moisture content. However, these devices are generally acknowledged to be somewhat inaccurate and especially unreliable at moisture levels above 30%.
Accordingly, it is a principal object of the present invention to provide a device for measuring wood moisture content which operates with improved accuracy and greater reliability at moisture levels above 30%.
It is another object of the present invention to provide a meter-type device for measuring wood moisture content which is of simple and durable construction; is easy, rapid, and convenient to use; and is otherwise well adapted to the purposes for which the same is intended.